1. Field of the Invention
Embodiments of the invention generally relate to optical communication subsystems, and more particularly, to optical interconnection devices.
2. Description of the Related Art
The manufacturing processes involved in generating optical systems generally requires precise alignment of lenses, prisms, mirrors, isolators, and other optical components within various mounting apparatuses. Precise alignment is particularly important in laser-based optical systems, as misalignment may interfere with optical isolation, which may reduce or eliminate the optical gain needed for proper laser operation and may increase system noise. Additionally, with regard to polarization and filtration processes involving crystals, the crystals often require precise alignment in order to achieve minimum insertion loss and maximum polarization parameters. Although optical isolators often use magnets to align the photons for increased polarization efficiency with respect to the crystal lattice, if the magnets are not properly aligned relative the lattice, polarization may nonetheless still be negatively affected and the return loss decreased.
Therefore, in order to minimize component alignment problems, specialized optical mounting devices are frequently used to secure optical components therein. For example, a retainer ring, spring-type retainer, or other means for exerting a biasing/securing pressure generally operates to secure the optical component within the mounting device, thereby reducing the chance that the optical component will be moved out of alignment after the initial assembly process is complete. However, the biasing pressure in conventional mounting devices is generally applied in a single direction, i.e., the component is biased against a fixed member in a unitary direction in order to prevent translational movement of the component. However, these configurations may still be subject to small perturbations in directions other than the biasing pressure direction, such as, for example, in a rotational direction or a direction orthogonal to the biasing direction. For example, many optical mounts (especially prism mounts) make use of a spring retainer, wherein the spring retainer contacts the top of the optical component urging it down against a base plate. In this configuration, the optical component is prevented from being translated in the direction of the biasing force, however, rotational movement and/or slipping of the lens horizontally is not restricted. Conversely, many optical isolator mounts secure their optical components at their perimeter, thereby preventing rotation, however, these mounting configurations may still be susceptible to translational movement or slippage. Another common optical component mounting technique is to clamp the optical component in place with a rod that urges the optical component against one or more base plates, where the rod is attached to a post with locking screws, and the rod in turn is securely attached to the base plates. However, the use of screws can be problematic, as they may loosen in time, particularly when they are exposed to the temperature cycling that often accompanies optical systems. Furthermore, the rod configuration generally offers only a unitary direction biasing/securing force, and therefore, it is again susceptible to rotational and horizontal translations.
Another common approach to mounting optical components is to use epoxy-based mounts. In these configurations, the optical component is placed in a mount and an epoxy is applied to the perimeter of the component. Once the epoxy cures, the component is generally affixed in the mount and is not susceptible to movement. However, although the use of epoxies is generally suitable for room temperature applications, epoxy mounts have shown weakness in environments where the temperature fluctuates, as epoxies and optical materials generally have different temperature coefficients of expansion. Thus, the epoxy may expand or contract at a different rate than the surrounding mount or the optical component itself, which can displace the optical component and potentially break the mounting bond.
Therefore, in view of the disadvantages of conventional optical mounting devices and methods, there is a need for a simple, easily manufactured, efficient, and cost effective optical isolator mounting apparatus that overcomes the disadvantages of conventional optical mounting devices.
Embodiments of the invention generally provides an apparatus for holding optical components. In one embodiment, the invention provides an inner sidewall of the body disposed between a first and second end of the body defining a first component holding region. The first component holding region is in an offset alignment with the bore, the inner wall is adapted to frictionally accept a first component therein and exert a biasing force thereon to maintain the first component in a desired optical alignment. The apparatus further includes an outer sidewall of the body disposed between the first and second ends. The inner and outer sidewalls define a second component holding region therebetween, wherein the inner and outer sidewalls are adapted to frictionally accept a second component therein and exert a biasing force thereon to maintain the second component in a desired alignment relative the bore.
Embodiments of the invention further provide an optical component mounting apparatus including a body having a bore formed longitudinally therethrough. The body includes a first end that includes a component holding region disposed in an offset alignment with the bore and is configured to receive an optical component therein. The component holding region includes a receiving diameter sized less than the diameter of the optical component to be inserted, wherein once the optical component is inserted, the component holding region is allowed to deform to the optical component diameter, which operates to mechanically secure the optical component within the component holding region.
Embodiments of the invention further provide an optical interconnect including a body having a longitudinal bore therethrough, a first end of the body includes an interior sidewall portion of the body defining a first component holding region adapted to deform when a first component is inserted to mechanically secure the first component therein. The first end further includes an exterior wall, wherein the interior wall and the exterior wall form a second component holding region therebetween that deform to mechanically secure a second component therein. The optical component also includes a second end of the body that includes an optical interface, and an exterior mounting section adapted to receive and mechanically couple a mating optical interconnect output to the optical interface.
Embodiments of the invention further provide a method for mounting an optical component within an internal sidewall of an optical body. The method generally includes inserting the optical component into a cavity defined by the internal sidewall, crushing a plurality of fingers extending from the internal sidewall between the optical component and the internal sidewall, and generating a predetermined clamping force between the crushed fingers and optical component, the predetermined clamping force having a magnitude calculated to secure the optical component within the cavity.